Contrary to internationalization (abbreviated i18n) which requires translators for each supported language, accessibility (abbreviated a11y) is partly handled automatically, independently of the types of handicaps. For instance, gnome applications and more generally all gtk applications are a priori "accessible" thanks to the ATK component which handles making GTK widgets accessible (via the standard AT-SPI interface).

A priori only. Indeed, even if all the content of the interface of some software is accessible, a lot of defects can make its use hard or even impossible.